Temperature control system



Fell 22, 1938- G. H. FISHER TEMPERATURE CONTROL SYSTEM Filed Sept. 5, 1935 AAAAAAL Patented' Feb. 22, 1938 UNITED STATES PATENT OFFICE TEMPERATURE CONTROL SYSTEM Application September 5, 1935, Serial No. 39,256

Claims. x (Cl. 236-91) This invention relates to temperature control systems of the type disclosed in the application of Daniel G. Taylor, Serial No. 512,887, led February 2nd, 1931.

I'he system disclosed in the above referred to Taylor application comprises an outdoor controller responsive to outdoor atmospheric conditions, including temperature, wind and solar radiation for controlling the temperature Within a building. Heating means are provided in the building for supplying heat to the building, and heating means are also provided in the outdoor controller for supplying heat to the outdoor controller. The two heating means are proportioned according to the heat lossesV from the building and from the outdoor controller. A thermostatic device is provided in the outdoor controller for Iresponding to the temperature within the outdoor controller and when this thermostatic device calls for heat both of the heating means are energized to deliver heat to the building and to the outdoor controller. Due to the proportional relationship of the heating means to the heat losses of the building and the outdoor controller, a denite temperature relation is maintained within the building and the outdoor controller so that by responding to the temperature of the outdoor controller the thermostatic device maintains a substantially constant or normal temperature Within the building.

Such a system gives excellent results when the outdoor temperatures are relatively low. However, due to the intermittent operation of the system, over-heating during mild weather is sometimes brought about, this over-heating being caused by the admission of a full charge of heating iiuid, such as steam, tothe radiators or heat exchangers within the building. This full charge of heating fluid admitted during mild weather necessarily causes over-heating of the building.

It is, therefore, an object of this invention to decrease the amount of heat delivered to the building during mild weather, whereby overheating of the building is prevented.

By decreasing the amount of heat delivered to the building during mild weather, the amount of heat delivered to the outdoor controller must likewise be decreased in order to maintain the proportional relationship existing between the heating eect of the heating means and the heat losses of the building and the outdoor controller. It is, therefore, another object of this invention to decrease the amount of heat delivered to the building and to the outdoor controller upon an increase in outdoor temperature.

It is another object of this invention to provide a control system for a heating system Wherein the control system causes intermittent operation of the heating system, and wherein means are provided for adjusting the operation of the heating system in accordance with outdoor temperature conditions to prevent over-heating of the building.

It is a further object of this invention to provide in a control system of the class described above, means whereby the automatic control of the system is rendered inoperative and the heating system is placed under manual control.

Other objects and advantages will become apparent to those skilled in the art upon references to the accompanying specification, claims and drawing, in which drawing is diagrammatically illustrated the preferred form of my invention.

The control system is shown as applied to a building having an outside wall I0, and a plurality of spaces or rooms II and I2, the temperatures of which are to be controlled. Located in the rooms II and I2 are radiators I3 which receive a supply of heatingiiuid, such as steam, through orices I4 from risers I6 under the control of manually operated valves I5. The risers I6 are connected into a header I'I which receives its supply of steam from a pipe I8 controlled by avalve I9. Steam is supplied to the above system by a pipe leading from some source of steam, not shown. The condensate from the radiators, or heat exchangers, I3 lmay be disposed of in any suitable manner through return pipes 2 I.

The valve I9 is operated by a. valve stem 22 which is connected to one end of a pitman 23. The other end of the pitman 23 is connected to a crank pin 24 mounted on a crank disc 25, carried by a shaft 26. The shaft 26 may be operated by a proportioning motor of the type shown and described in application Serial No. 673,236, led by Lewis L. Cunningham, on May 27th, 1933.

For purposes of illustration in this application, the proportioning motor is shown as comprising a gear 21 mounted on the shaft 26 and rotated through a reduction gear. train designated at 28 Y elled gear 34 carrying an abutment member 35. The abutment member 35 is equipped with a slider 36 which is adapted.v to slide across a balancing potentiometer coil 31. The abutment member 13 5 also carries ngers 38 and 39 which are adapted to engage, respectively, contacts 48 and 42. Engagement of the finger 38 with the contact 48 breaks contact between the contact 48 and a stationary contact 4|. Likewise, movement of the nger 39 into engagement with the contact.

42 breaks contact between the contact 42 and a stationary contact 43. The contacts 48, 4|, 42 and 43 form limit switches to limit the movement of shaft 26 in a manner which will become evident hereinafter,

Leading from some source of power, not shown, are line wires 44 and 45, the line wire'44 being connected by a wire 46 to a pivoted switch arm 41. The switch arm 41 is adapted to engage spaced contacts 48 and 49, the contact 48 being connected by a wire 58 to the contact 42, and the contact 49 being connected by a wire 5| to the contact 4|. The contact 43 is connected by a wire 52 to one end of the field winding 32, and the contact' 48 is connected by a wire 53 to one end of the field winding 3|. 'I'he other ends of the field windings 3| and 32 are connected together and by a wire 4 to the line wire 45.

Movement of the-switch arm 41 into engagement with the contact 48 completes a circuit from the line wire 44 through Wire 46, switch arm 41, contact 48, wire'58, contacts 42 and 43, wire 52, field winding 32 and wire 54, back to the other line wire` 45 to cause energization of the eld winding 32 to movethe valve |9 towards an open position. Movement of the switch arm 41 into engagement with ,the contact 49 completes a circuit from the line wire 44 through wire 46, switch arm 41, contact 49, wire 5|, contacts 4| and 48, wire 53, field winding 3| and wire 54, back to the line wire 45 to energize the eld winding 3| to move the valve |9 towards a closed position. When the valve I9 is moved to either full closed or full open position the limit switches are opened. to de-energize the field windings 3| or 32 to prevent overtravel of the proportioning motor.

Located outsideA of the building, so as to be subject'to the same atmospheric conditions as the building, is an-outdoor controller 55. The outdoor controller 55 comprises a block 56 which is "hollowed out to receive a container 51. Located within the container 51 is a bimetallic element 58 mounted on a post 59. 'I'he bimetallic ele- Y outside temperature, but will respond directly to the temperature ofthe blockr56. The block 56 is cooled by the outdoor atmosphere and is heated by .means of a heater which may be in the form of an electrical resistance heater 65. The outdoor controller 55 is enclosed within a weathertight casing diagrammatically shown at 66.

Also located outside of the building so as to respond to outdoor temperature conditions is an outdoor controller 61. This controller 61 comprises a bimetallic element 68 suitably mounted on a post 69 for operating'an arm 18. The arm 18 carries a slider 1| adapted to slide acrossa resistance coil 13, and also carries a second slider 12 adapted to slide across a resistance coil 14. Upon an increase in outdoor temperatures `the sliders 1| and 12 are moved to the left with respect to their resistance coils 13 and 14 inthe direction of the character H and upon a decrease in temperature they are moved to the right in the direction of the character C. The elements of the outdloor controller 61 -may be suitably mounted in a weather-tight casing 15, to prevent deterioration of the same.

Line wires leading from some source, not shown, are designated at 16 and 11. The primary 18 of a step down transformer 19 having a secondary 88 is connected across the line wires 16 and 11. A relay coil is designated at 8| for operating switch arms 82, 83 and 84 with respect to ,contacts 85, 86, 81 and 88. Upon energization df the relay coil 8| the switch arms 82, 83 and 84 are l moved to the left into engagement with the contacts 85, 86 and 81, respectively. Upon de-energization of the relay coil 8|, the switch arms 82, 83 and 84 are moved out of engagement with the contacts 85, 86 and 81, respectively, and the switch arm 84 is moved into engagement with the contact 88. One end of the secondary 88 is l connected by a wire 98 to the adjustable contact 62 of the outdoor controller 55. The other adjustable contact 63 is connected by wires 9| and 92 to one end `of the relay coil 8|. The other end of the relay coil 8| is connected by a wire 93 to the other end of the secondary 88. 'I'he bimetallic element 58 is .connected by a wire 94 to the contact 85 and the switch arm 82, associated with the contact 85, is connected by a Wire 95 to the junction of wires 9| and 92.

Also connected across the line wires 16 and 11 is the primary 96 of a step-down transformer 91, having a secondary 98. One end of the secondary' 98 is connected by a wire 99 to the contact 86. The switch arm 83, associated with the contact 86, is connected by a wire |88 to one end of the heater 65. The other end of the heater 65 is connected by a wire |8| to the slider 1| of the outdoor controller 61. 'The resistance coil 13, associated with the slider 1|, is connected by a wire |82, variable resistance |83 and a wire |84 to the other end of the secondary 98.

Upon a decrease in the temperature of the block 56 of the outdoor controller 55, the contact 68 is moved into engagement with the contact 62, and upon a further decrease in temperature, the contact 6| is moved into engagement with the contact 63. This causes completion of a circuit from the secondary 88 through wire 98, contacts 62, 68, 6| and 63, Wires 9| and 92, relay coil 8| and Wire 93, back to the secondary 88. This causes energization of the relay coil 8| to move the switch arms 82, 83 and 84 into engagement with the contacts 85, 86 and 81. Movement of the switch arm 82 into engagement with the contact 85 completes a maintaining circuit from the secondary 80 through wire" 98, contacts 62 and 68, bimetallic element 58, 4Wire 94, contact 85, switch arm 82, wires 95 and 92, relay coil 8| and wire 93, back to the secondary 88. Completion of this circuit maintains the relay coil 8| energized until contact between the contacts 68 and 62 is broken. Movement of the switch arm 83 into engagement lwith the contact 86 causes completion of a circuit from the secondary 98 through wire 99, contact 86, switch arm 83, wire |88, heater 65, Wire |8|, slider 1|, resistance 13,

back to the secondary 98. 'I'his causes energization of the heater 65 to cause heating of the block 56. When the temperature oi the block 56 has risen suiciently high so as to break contact between the contacts 60 and 62, the relay coil 8| is de-energized to move the switch arms 82, 83 and 84 out of engagement with the contacts 85, 86 and 81, and to move the switch arm 84 into engagement with the contact 88. The variable resistance |03 provides manual means for adjusting the heating effect of the heating element 65.

Connected across the line .wires 44 and 45 is a primary |06 of a step-down transformer |01 having a secondary |08. One end of the secondary |08 is connected by Wires |09 and |I0 to one end of a coil III. In a like manner, the other end of the secondary |08 is connected by wires ||2 and ||3 to one end of a coil ||4, the

wire |28 to the contact 81.

other ends of the coils and |I4 being connected together. The coils and ||4 control the operation of an armature or core H5, which is connected by means of a spring ||6 to a pivoted switch arm ||1. The switch arm ||1 is adapted to engage contacts |I8 and IIS, the

arrangement being such that when the coil |I| is energized more than the coil I|4 the switch arm I I1 is moved into engagement with the contact |8, and when the coil I I4 is energized more than the coil |I| the switch arm ||1 is moved into engagement with the contact II9. When the coils and |I4 are equally energized, the switch arm |I1 assumes a position mid-way between the contacts I|8 and ||9 as shown in the drawing.

The outer end of the coil |II is connected by'a wire |20, a protective resistance |2|, a wire |22, a variable resistance |23', and a wire |23 tothe contact 88. The outer end of the coil ||4 is connected by a wire |24, a protective resistance |25, wires |26 and |21, the resistance 14, slider 12 and The switch arm 84 which cooperates with the contacts 81 and 88, is connected by a wire |30 to an automatic contact I3 I A slider |32 manually operated by a knob |33 is adapted to en-gage the"automatic contact |3| and is connected by wires |34 and |35 to the junction of coils ||I and |I4. The junction of the protective resistance |2I and the wire |22 is connected by a wire |36 to the right hand end of the balancing potentiometer coil 31. Likewise, the junction of wires |26 and |21 is connected by a wire |31 to the left hand end of the balancing potentiometer coil 31. The slider 36, associated with the balancing potentiometer coil 31, is connected by a wire |38 to the junction of Wires |34 and |35. The Wire |22 and the left `hand end of variable resistance |23 are connected by a wire |39 to the right hand end of a resistance |40, the other end of the resistance\|40 being connected Yby awire I4| to the junctions of wires |26, |21 and |31. ,When the slider |32 is moved out of engagement with the automatic contact |3| and into engagement with the resistance coil |40 manual control of the system is made possible in a manner to be brought out more clearly hereafter.

The junction of wires |09 and I|0 is connected by a wire |42 to one end of a coil |43, and likewise the junction of wires ||2 and ||3 is connected by a wire |44 to one end of a coil |45. The other ends of the coils |43 and |45 are connected together and by a resistance |46 and a wire |41 to the pivoted switch arm |1. The coils |43 and |45 are adapted to control an armature or core |48, which is connected by means of a spring |49 to the pivoted switch arm 41 so that when the coil |43 is energized more than the coil |45 the Switch arm 41 is moved into engagement with the contact 49., and when the coil |45 is energized more than the coil |43, the switch arm 41 is moved into engagement with the -contact 48. When the coils |43 and |45 are equally energized switch arm 41 assumes a mid-position between the contacts 48 and 49 as shown in the drawing. The contact ||8 associated with the pivoted switch arm ||1 is connected by a wire |50 to a small number of turns of the coil I||, and the contact I I9 is likewise connected by a wire |5| to a small number of turns of the coil |I4.

From the above it is seen that the upper end of the secondary |08, the right hand end of the coil III, the contact 88 and the right hand end of the balancing potentiometer coil 31 are connected together, and that the lower end of the secondary |08, the left hand end of the coil I|4, the contact 81 and the left hand end of the balancing potentiometer coil 31 are connected together. The slider 36, the switch arm 84 and the junction of coils and II4 are connected together during automatic operation of the system. From the above connections it is seen that the balancing potentiometer coil 31, the coils I and ||4 `in series and the secondary |08 are connected in parallel.

With the sliders 1I and 12 located in their eX- treme right hand positions with respect to the resistances 13 and 14 by reason of cold outdoor temperatures and with the remaining parts in the position shown in the drawing, the valve I9 is closed, the switch arm 84 is in engagement with the contact 88, the slider 36 is in the extreme left hand position with respect to the balancing potentiometer coil 31, the coils and I|4 are equally energized and,- therefore, the switch arm I|1 is mid-way between the contacts ||8 and ||9. Upon energization of the relay coil 8| to move the switch arm 84 into engagement with the contact 81 and by reason of the parallel relationship pointed out above, the coil ||4 is partially short circuited by a circuit extending from the junction of coils and I|4 through wires |35 and |34, slider |32, automatic contact |3|, wire |30, switch arm 84, contact 81, wire |28, slider 12, wires |21 and |26, protective resistance |25 and wirel24, back to the coil ||4. This circuit decreases the energization of the coil ||4 and increases the energization of the coil to move the switch arm ||1 into engagement with the contact ||8. ment of the switch arm I |1 into engagement with the contact I I8 completes a circuit from the secondary |08 through wires I|2 and |44, coil |45, resistance |46, wire |41, switch arm I I1, contact I8, wire |50, a small numberv of turns of coil I I and wires |I0 and |09, back to the secondary |08. Completion of .this circuit places the resistance |46 and the small number of turns of I coil |I| in parallel with coil |43 whereby to decrease the energization thereof, and increase the energization of the coil |45 in respect thereto.

`'l'his causes movement of the switch arm 41 into engagement with contact 48 to cause energization Moveof the eld winding 32, in the manner pointed with respect to the balancing potentiometer coil 31. Movement of the slider 36 towards the right with respect to the balancing potentiometer coil 31 causes a partial short circuiting of the coil I to decrease the energi'zation thereof and to increase the energization of the coil II4, it being remembered that movement of the switch arm 84 I into engagement with the contact 81 increased the energization of the coil I II and decreased the energization of the coil II4. When the slider 36 has moved suiliciently far to the right to rebalance the energization of coils III and -II4 the switch arm |I1 is moved out of engagement with the contact |I.8 to the midposition shown in the drawing. This causes substantially equal energization of the coils |43 and |45 to move the switch arm 41 out of engagement with the contact 48 to stop energization of the field winding 32, whereby the valve I9 is maintained in its open position. Also, the small number of turns lof coil III is de-energized so that switch arm |46, wire |41, switch arm II1, contact II9, wirey I5I, a small number of turns of coil I I4 and wires ||3 and II2 back to the secondary |08. Completion of this circuit places resistance |46 and the small number of turns of coil I4 in parallel with coil |45 whereby to decrease the energization thereof and increase the energization of coil |43 to move the switch arm 41 into engagement with the contact 49. This causes energization of the field `winding 3|, in the manner pointed out above to'move the valve I9 towards a closed position. Energization of the small number of turns of coil I|4increases the pressure between switch arm I-'I1' and contact II9. Movement of the valve 'I9 towards a closed position causes left hand movement of the slider 36 with respect to the balancing potentiometer coil 31 to partially short circuit the coil |I4 to decrease the energization thereof and increase the energization of coil III, it being remembered that the coil |I4 was energized more than the coil"1 I II by reason of movement of the switch arm 84 into engagement with the contact 88. When the slider 36 has moved suiliciently far to the left to cause a-substantial re-balancing of the coils III and II4, the switch arm I|1 is moved out of engagement with the contact II9 to balance the energization of the coils |43 and |45. This causes movement of the switch arm 41 cut of engagement with the contact 49 to the midposition as shown in the drawing to de-energize the field winding 3| to maintain the valve I 9 in a closed position. Separation of switch arm |I1 from contact I|9 also interrupts the circuit through the small number of turns of coil |I4 so that switch arm I|1 moves yfurther from contact ||9, as pointed -out above. The circuits through coils |43 and |45 pass through a small number of turns of the coils I I I and II4 to forcibly hold the switch arm I|1 in engagement with the contacts I I8 or ||9, whereby relay chatter is eil'ectively prevented. It is also noted that movement of the switch arm 84 into engagement with contacts 81 and 88 causes suhstantxauy comprate short circulungof' the coils ||4 and I I I, respectively, so that in order t0 re-balance the coils II4 and III slider 36, operated by the proportioning motor, must move to either extreme position with respect to the balancing potentiometer coil 31. Complete short circuiting is prevented by the protective resistances |2I and |25 which protect the circuits. Therefore, the valve I9 is moved to either a full closed position or a full open position by the switch arm 84 engaging the contact 81 or 8B. This would cause a full charge of heating fluid to be admitted to the radiators, or heat exchangers, I3, Whenever the relay coil 8| is energized. As pointed out above, this is not desirous in mild weather since the full charge of steam being admitted to the radiators I3 may cause overheating of the building. In order to remedy this, I have provided a means whereby the valve I9 is moved only to a partially open position during mild weather. This mode of operation is accomlplished by the slider 12 and the resistance 14.

Slider 12 is moved by the thermostatic element 68 to add resistance to the circuit which causes short circuiting of the coil |I4 when the outdoor temperature increases above a predetermined value. Therefore, as the outdoor temperature increases, the coil ||4 is not substantially completelyshort circuited as pointed out above and therefore complete right hand movement o'f the slider 36 with respect to the balancing potentiometer coil 31 is not required to rebalance the coils III and II4. It follows that the valve I9 is only moved to a partially open position when the thermostatic element 68 of the controller 61 places resistance in circuit with the coil II4. Since more of the resistance 14 becomes effective in this mann .Ir upon greater increases in outdoor temperature, opening movement of the valve I9 will be limited toa greater extent so that on extremely mild days the valve I9 will not be opened as far as on those days when the weather is not so mild.

The control system is so adjusted by manual l manipulation of the variable resistances |03 that the amount of heat delivered to the building and the amount of heat delivered to the outdoor controllerA 55 is proportional to the amount of heat loss from the building and the amount of heat loss from the outdoor controller'55. This proportional relationship must be maintained in order to maintain a substantially constant temperature within the building, since the thermostatic element 58 controls both the supply of heat to the building and the supply of heat to the outdoor controller 55. Since the amount of heat delivered to the building. is decreased as the outdoor temperature increases in the manner pointed out above, the amountv of heat delivered to the outdoor controller 55 'must likewise be decreased as the outdoor temperature increases to maintain this proportional relationship. Therefore, the resistance 13 and theslider 1I are connected in series with the heater 65 so that when the slider 1| is moved to the left with respect to the resistance 13 by an increase in outdoor temperature, the amount of heat delivered to the block 56 is thereby decreased. Since both sliders 1I and 12 are operated conjointly by the thermostaticv element 68, the amount of heat delivered to the building and to the outdoor controller are proportionately reduced, and the predetermined proportionall relationship between the heat supplies and the heat losses is maintained. By reason of this construction, the building is maintained at all times at a substantially constant temperature and over-heating of the building during mild Weather is prevented.

'Ihe variable resistance |23 is provided in circuit with the coil I I and may be adjusted to add resistance to the circuit through the coil H5 to prevent substantially complete short circuting of the coil |I5. This prevents complete closing movement of the valve I9 in the same manner that -variable resistance I4 prevents complete opening movement of the valve I 9. Therefore by adjusting the variable resistance |23' a small amount of steam maybe permitted to flow through the radiators at all times during extremely cold weather. If desired, the variable resistance |23 may be operated by an outdoor thermo/stat to limit the closing movement of the valve during extremely cold weather.

Movement of the slider I 32 by manual manipulation of the knob |33 out ofV engagement with the automatic contact, and into engagement with the resistance coil |40, breaks the circuit to the switch arm 84 to render automatic control of the valve I9 inoperative. Since the left hand end of the coil |40 is connected to the coil II4, the right,hand end thereof is connected to the coil III and the slider |32 is connectedto the junction of coils III and II4 manual movement of the slider |32 along the coil |40 will cause operation of the valve I9. Movement of the slider |32 to the left With respect to the coil |40 causes partial short circuiting of the coil I|4 to increase the energization of the coil III and decrease the energization of the coil I I4 to cause opening movement of the valve I9 in the manner pointed out above. Likewise, right hand movement of the slider |32 with respect to the coil |40 causes partial short circuiting of the coil III to decrease the energization thereof and increase the energization of the coil II4 to cause closing movement of the valve I9. The coils I I I and II4 are rebalanced by the slider 36 co-acting With the balancing potentiometer coil 31 in the manner pointed out above. Since the potentiometer coils |40 and 3'I are connected in parallel and since short circuiting of the coils III and II4 may not be complete, the valve I0 may be made to assume any given position by manipulation'of the slider |32 with respect to the coil In addition to providing an automatic control system wherein the temperature Within a building is maintained 'substantially constant, and wherein over-shooting of the building temperature during mild weather is prevented, I have provided means whereby the automatic control may be rendered inoperative and the building heating means placed under manual control;

Although I have disclosed one form of my invention, various modications thereof may become apparent to those skilled in the art and, consequently, this invention is to be limited only by the scope of the appended claims and the prior art.

I claim as my invention:

l. In a temperature controlsystem for a space, the combination of means for supplying heat to the space, a controller having heat supplying means and thermostatic means, the thermostatic 'means controlling both heat supplying means,

the space, a controller having heat supplying means and thermostatic means, the thermostatic means controlling both heat supplying means, and thermostatic means outside of said space for adjusting both of said heat supplying means.

3. In a temperature control system for a building, the combination of temperature changing means for the building, an outdoor controller subject to the same atmospheric conditions as the building and having temperature changing means and thermostatic means, the thermostatic means controlling both temperature changing means, and thermostatic means for adjusting both temperature changing means.

4. In a temperature control system for a building, the combination of temperature changing means for the building, an outdoor -controller subject to the same atmospheric conditions as the building and having temperature changing means and thermostatic means, the thermostatic means controlling both temperature changing means, and thermostatic means responsive to outdoor temperatures for adjusting the temperature changing effect of both of said temperature changing means.

5. In a temperature control system for a building, the combination of valve means for controlling the supply of heating fluid to the building, means responsive to outdoor conditions for opening or closing said valve means, and means responsive to outdoor conditions for gradually limiting the opening movement of said valve means in accordance with changes in outdoor conditions.

6. In a temperature control system for a space, the combination of means for supplying heat to said space, thermostatic means including heating means for controlling said heat supplying means to admit heat to said space upon a call for heat, and means responsive to temperatures outside of said space for gradually limiting the amount of heat supplied to said space in proportion to increases in outside temperatures.

'7. In a temperature control system for a building, the combination of means for supplying heat to said building, control means responsive to outdoor conditions for controlling said heat supplying means to admit heat to said space upon a call `for heat by said control means, and means responsive to outdoor conditions for gradually regulating the amount of heat so admitted in accordance with changes in outdoor conditions.

8. In a temperature control system for a space, the combination of means for supplying heat to said space, thermostatic means including heating means for controlling said supplying means to admit heat to said space upon a call for heat, and

sponsive to increasing outdoor temperature conditions for gradually decreasing the amount of heat so admitted.

10. In a temperature control system for a building, the combination of heat supplying means for said building, an outdoor controller subject to the same atmospheric conditiongas saidv building, said outdoor controller including thermostatic means and heat supplying means, said thermostatic means controlling both heat supplying means, whereby heat is intermittently supplied to said building and said controller to maintain a substantially constant temperature in said building, and means responsive to outdoor temperatures for adjusting the amount of heat delivered to the building and the outdoor controller.

` 11. In a temperature control system for a building, the combination of heat supplying means for said building, an outdoor controller subject to the same atmospheric conditions as said building, said outdoor controller including thermostatic means and' heat supplying means, said thermostatic means controlling both heat supplying means, whereby heat is intermittently supplied to said building and said controller to maintain a substantially constant temperature in said building, and means responsive to outdoor temperatures to decrease the amount of heat delivered to the building and the outdoor controller as the outdoor temperature increases.

12. In a temperature control system for a building, the combination of temperature chang-4 means for said building, an outdoor controller subject to the same atmospheric conditions as said building, said outdoor controller including I thermostatic means and heat supplyingmeans, said thermostatic means controlling both heat supplying means, whereby heat is intermittently supplied to said building and said controller to maintain a substantially constant temperature in said building, means responsive to outdoor temperatures for adjusting the amount of heat delivered to the building and the outdoor controller, and means for rendering said thermostatic means inoperative to control said building heat supplying means and for controlling said building heat supplying means manually.

14. In a temperature control system for a building, the combination of valve means for controlling the supply of heat to the building, an outdoor controller subject to the same atmospheric conditions as the building and including heating means and thermostatic means, said thermostatic means simultaneously and intermittently operating said heating means and opening said valve means, and means to limit the opening movement of said valve means and to decrease the heating effect of said heating means upon the occurrence of mild atmospheric conditions.

15. In a temperaturecontrol system for a space, the combination vof means for supplying heat to the space, a controller having heat supplying means and thermostatic means, the thermostatic means controlling both heat supplying means, thermostatic means outside of said space for regulating the heating effect of both of said heat supplying means, and means for controlling said heat supplying means for the space independently of said thermostatic means.

GEORGE H. FISHER. 

